DK169467B1 - Method for controlling a high pressure cleaner, as well as a high pressure cleaner for carrying out the method - Google Patents

Abstract

In a high-pressure cleaner, in order to control additional equipment, such as chemical doser or burner, from a hand spray gun without any special control lines, it is proposed to connect a second closable flow path in parallel with the normal flow path through the spray nozzle, to determine the pressure rise time in the cleaning fluid after the switching on of the high-pressure pump and to generate a control signal by opening the second flow path to extend said rise time compared with the rise time when the second flow path is closed; furthermore, a high-pressure cleaner is proposed for implementing this process.

Description

. Λ in DK 169467 B1

The invention relates to a method of the kind specified in the preamble of claim 1 for controlling a high-pressure cleaning apparatus, and a high-pressure cleaning apparatus of the kind specified in the preamble of claim 3 for practicing the method.

Such high-pressure cleaning apparatus usually includes a heat exchanger with a burner as well as a device for dosing the addition of chemicals so that the delivered cleaning medium can optionally be heated and / or may contain a chemical. For high pressure washers of this type, the user should optionally be able to activate the heat exchanger and / or admix the chemical from the hand spray gun, which also has a blocking or dosing valve in 1 for the cleaning medium itself. Since the heat exchanger and the chemical mixing device are usually disposed in the high pressure cleaning unit itself, which communicates with the hand spray gun through a usually quite long high pressure hose, separate signal transfer means for transmitting 20 control signals from the hand spray gun and / or the spray gun must be provided. for the device for incorporating the chemical into the cleaning medium. It is e.g. known to place a high frequency transmitter in the hand spray gun and a corresponding receiver in the high pressure cleaning unit so that from the transmitter 25 wire or via a high pressure hose surrounding the transmitter signals can be supplied. In other known embodiments, it is known to transmit electrical control signals to place control lines in the casing wall of the high pressure hose. However, these known embodiments are constructively complicated and thus costly and prone to failure.

Furthermore, it is known to regulate the dosed addition of chemicals by the pressure in the cleaning medium itself. Hereby a varying swirling effect is utilized in DK 169467 B1 2 the spray nozzle of the high-pressure line to provide different high pressures in the high-pressure line, with cleaning chemical being applied at certain pressures in the cleaning medium. However, this is disadvantageous to the user insofar as, at a certain pressure, such as e.g. corresponds to a specific nozzle shape, always forcibly mixed with chemical, while at another pressure no chemical can be added to the cleaning medium.

It is the object of the invention to provide a method in which the burner gun burner can be controlled without additional transfer means without the burner of the heat exchanger and / or the chemical dosage in the high pressure cleaning unit, without limiting the use of the high pressure cleaning device in the amount of cleaning agent delivered. and operating pressure. This object is achieved by the measures specified in the characterizing part of claim 1. When the high-pressure line is started with an open high-pressure pump, it takes a normal time of 0.3 seconds until the normal operating pressure is provided in the cleaning medium in the high-pressure line. Without the additional flow passage through which high pressure medium can flow parallel to the spray nozzle, this pressure rise time interval is increased. This extension of the pressure rise time can be determined and utilized to produce a control signal which e.g. is only produced if the pressure rise time is increased by a certain time interval. This control signal can then e.g. is used to activate the dosed chemical additive or to start the burner.

The provision of the control signal can be simply determined by the operator by releasing or blocking the second flow passage as desired before starting the high-pressure pump.

DK 169467 Pg 3

Without the measure specified in claim 2, it is achieved that in normal operation no cleaning medium flows out through the second flow passage.

The high pressure cleaning apparatus of the kind specified in the preamble 3 of claim 3 is peculiar to the part of the drawing known in claim 3. According to the invention, the pressure-sensitive signal transducer may have two pressure sensors which at different pressures supply each time signal with its own signal. The time control can in a known manner control the time distance between the two signals and compare the time interval with a given time interval so that a control signal is produced if the given time difference value is exceeded.

Without prejudice to claims 5 and one, it is achieved that a time signal is applied to the time control means and after a certain time an opening signal 1 is provided, and that the time interval between the two signals being emitted can be determined in the same way as the time interval between the successive signals from two pressure sensors or from two successively activated switches.

According to the invention, a manually operated shut-off valve may be provided for the second flow passage.

This shut-off valve can be easily set by the operator who can detect the state of the valve in the second flow passage.

In the embodiment according to claim 11, it is automatically ensured that the second flow passage is blocked when the pressure reaches the operating value, so that all the cleaning medium is delivered via the first flow passage.

Without prejudice to claim 12, it is achieved that the second flow passage, even when the shut-off valve is open, is released only when the pressure reaches a certain minimum value and that the second flow passage is again blocked as soon as a maximum pressure is exceeded.

In the embodiment according to claim 13, in the form of the high pressure cleaning apparatus according to the invention, step-by-step pressure rise times can be provided which can be used for generating several control signals, e.g. a control signal for starting the burner and a second control signal.1 for activating the dosed chemical additive.

In the following, the invention is explained in more detail with reference to the drawing, in which fig. 1 is a schematic longitudinal sectional view of a hand-operated spray gun of one embodiment of the high-pressure cleaning apparatus and further illustrates essential parts of the high-pressure cleaning system of the high-pressure cleaning apparatus; and FIG. 2 schematically shows time-dependent pressure variations in the cleaning medium.

The FIG. 1, the handgun gun shown in its entirety 20 is denoted by 1 and connected to a flexible high pressure line 2 which opens into a cavity 3 in the gun 1. The cavity 3 stands via an opening 4, a branch space 5 and a throttle location 6 in connection with a spray passage 7 which opens into the open air via a spray nozzle 8.

Throughout the cavity 3, a longitudinal maneuvering rod 9 is projected therefrom, which protrudes from the cavity at a location where there is a sealing means between the rod and the spray gun housing. Inside the cavity 3 is a valve body 10. At the inner end of the rod 30, a throttle body 11 is placed on the inner end of the rod 30. On the rod 9 a cavity is placed in the cavity 9 in the cavity. screw compression spring 12, one end of which abuts against valve body 10 and the opposite end of which adjoins an end wall 13 of cavity 3, so that the spring seeks to push valve body 10 against the opening 4 5 to block it. In this position, the throttle body 11 extends in its total length into the area previously designated as the throttle location 6 of the spray passage 7 as shown in FIG. 1. The end portion 14 of the maneuvering rod 9 opposite the throttle-1 squirrel 11 is passed through a maneuvering arm 15 10 pivotally mounted in the spray gun 1 and protrudes therefrom. On the end portion projecting on the rod 9 of the rod 9 is a stop body 16 for the arm 15. When pivoting the maneuver arm 15, the rod 9 can be displaced against the action of the compression spring 12 in such a way that both the valve body 10 is removed from the opening 4 and released, and partly the portion which the throttle body 11 projects into the throttle region 6 is diminished. Thereby, the high pressure passage 7 is opened simultaneously with the amount of cleaning medium which can pass the throttle location 6 is adjustable by the rod 9 being displaced more or less by the maneuvering arm 15.

In a channel 17 extending perpendicular to the longitudinal axis of the cavity 3 is rotatably mounted a valve body 18 with a central blind bore 19, the open end of which communicates with the branch space 5. The wall of the valve body 18 18 has a through radial passage 20 between the blind bore 19 and the outside of the valve body. On both sides of the passage 20, the valve body 18 is sealed to the wall of the channel 17 by means of sealing means 21 and 22. Above the passage 20, the wall 30 of the valve body 18 has an additional radial through passage 24 which is circumferentially disposed with respect to the passage 20. The valve body 18, by means of a handle 23 projecting from the spray gun 1 can be rotated in the channel 17, thereby being brought into various positions, which are described in greater detail below.

At the height of the first passage 20, there is a connecting channel 25 through which the passage 20 and thus the channel 17 can be connected to one end 5 of a valve chamber 26, the opposite end of which communicates with an outflow channel 27 in the free flow. At the transition between the valve chamber 26 and the channel 27, a valve seat 28 is formed. At the connecting channel 25, the valve chamber 26 has an annular venous seat 29. A valve body 30 is arranged in the valve chamber 26 with an end portion 30 which is located close to the valve seat 29 with large diameter and a remaining small body valve body portion.

Wait the small diameter portion of the illuminator is surrounded by a screw pressure spring 31, one end of which rests on a vented face in the chamber 1 and the other end abuts the large diameter portion of the valve body 30 and seeks to press it against the valve seat. 29 as shown in FIG. 1. The valve body 30 may be displaced toward the outflow channel 27 against the action of the compression spring 31 for blocking the outlet channel 27. The valve body portion 30 nearest to the valve seat 29 forms a throttle member in the cylindrical valve chamber 26. For blocking the outlet channel 27, the valve body member having the large diameter 25, which corresponds approximately to the diameter of the valve chamber 26, a peripheral groove 32 having a small cross-sectional area.

In an alternative embodiment, the outer diameter of the valve body located closest to the seat 29 may be somewhat smaller than the inner diameter of the valve chamber 26, so that there will be a ring gap acting between them.

The first passage 20 in the valve body 18 can be connected by rotation thereof with the passage 25 and through it with the valve chamber 26 and the outlet duct 27.

DK 169467 B1 7

Also, the second passage 24 in the vent 11 squirrel 18 can be connected to a passage 33 corresponding to the valve chamber 26, in FIG. 1 is not visible chamber which is connected to the surrounding atmosphere via an outflow line 34. Also in this valve chamber, which can be brought into contact with passage 24 therein through the passage 33 by turning the valve bearing 18, a vent is provided. corresponding to the vent in the body 30.

Thus, by appropriate rotation of the valve body 18 in the duct 17, the branching space 5 can be connected either via the first passage 20 in the wall of the valve body 27 to the first outflow channel 27 or via the second passage 24 of the valve body 18 to the second outflow channel 34. In addition, by turning the vent in the generator 18 to an appropriate position, the branch space 5 is blocked against both outflow channels 27 and 34.

The high-pressure line 2 is connected to the pressure side 35 of 20 a high-pressure pump 36, to which a cleaning medium is to be injected from a suction line 37. In addition, the high pressure line 2 communicates with a pressure equalizing container 38 and with a pressure switch 39 only schematically shown in the drawing for starting and stopping the high-pressure pump 36. Finally, the high-pressure line 2 is connected to a chamber 40 which is disposed therein and The piston 41 sealed against the chamber wall is divided into two chamber portions 42 and 43. The high pressure conduit 2 communicates with one chamber portion 42, while in the other part 43 of the chamber 30 is provided a screw pressure spring 44, which with one end abuts the piston 41 and with the other end towards the respective end wall of the chamber, and which seeks to push the plunger 41 against a stepping surface 45 in one chamber.1 42.

DK 169467 B1 8

A piston rod 46 connected to the plunger 41 protrudes from the second chamber portion 43 and has a constriction 47 outside the latter. In the proximity of the protruding portion of the piston rod is arranged a switch 48 with a switch-3 member 49 which is actuated by the piston rod and which is released when the piston rod constriction 47 is adjacent to the switching means 49. The switching 48 is connected to a timer 50 shown only diagrammatically in the drawing.

As the piston 41 is displaced, the timer 50 from the switch 48 receives end and end signals, respectively. The time sensor determines the time intervals between these signals. The time intervals are compared to a fixed value, and when the time exceeds a certain value, the timer 50 outputs a control signal which, through a control line 15 51 e.g. a device for dispensing a chemical or a burner in a heating device in the high-pressure cleaning apparatus is not shown in the drawing.

In the following, in connection with FIG. 2 shows the operation of the high-pressure cleaning apparatus; FIG. 2 schematically shows the temporal pressure losses in different operating modes. For simplification of production, all processes are shown in a straight line and not on the actual scale.

First, the normal operation is explained, in which the branch space 5 is neither in contact with the outflow channel 27 nor with the outflow channel 34. This operating state is shown in FIG. 2 indicated by the through curve denoted by 1. If the high pressure pump 36 is released with released opening 4, due to the swirling effect in the nozzle opening 8, a pressure is generated in the high pressure line 30 2. This pressure is hereinafter referred to as operating pressure.

Pg. The operating pressure of the cleaning medium in the high pressure line is maintained as long as the opening 4 is free. This operating pressure is somewhat dependent on the variable throttle effect DK 169467 B1 9 at the throttle location 6, for the sake of clarity, however, a constant operating pressure Ρβ is assumed for the following.

During the pressure increase up to the operating pressure, the cleaning fluid displaces the plunger 41 in the chamber 40 against the action of the spring 44. The dimensioning is chosen so that initially with actuated switch 48, it is no longer affected by the piston rod 46 when the pressure has risen to a lower limit value Pu, at which the narrowing 47 of the piston rod 10 is located beyond the actuator 49 of the switch 48. As soon as the pressure when it reaches an upper limit value Pq, the switch 48 is again affected by the piston rod 46. During the pressure rise, the timing means 50 is then supplied with two signals, namely at the time t ^ 15 a signal corresponding to the lower limit value Pu and at the time t ^ g. limit value PQ corresponding signal. In the timing means 50, in known manner, by electronic means, the time interval t1 is determined between the times t1 and t2 g. Thus, the time circuit determines the pressure rise time t ^ between the lower limit value Pu and the upper limit value P.

The time means 50 compares this pressure rise time t ^ with a nominal value selected such that it is greater than t ^. If the pressure rise time is shorter than the normal value, the timing means 50 does not output a control signal for dosed mixture of chemical into the cleaning medium and / or for starting the burner.

During continued operation, the operating piece Pg is maintained as long as the user keeps the handle 15 activated. When the operator releases the handle 15, the opening 4 is blocked so that a higher pressure is produced in the high pressure line 2. As soon as this increased pressure reaches above a value Pucj, the pressure switch 39 is thereby activated, whereby the high pressure pump 36 is stopped. Since the high-pressure line 2 is blocked in this operating state, the pressure in the cleaning liquid will continue to correspond to the pressure Py ^, deliberately ignoring in reality inevitable leakage losses.

5 When the operator again releases the opening 4 by the handle 15, the pressure drops abruptly. When the pressure decreases to a value P 1, the pressure switch 39 gives a signal for starting the high-pressure pump so that the pressure is increased again in the manner described above, 10, which in FIG. 2 is shown by curve la.

To adjust the apparatus for a different mode of operation, the valve body in the channel 17 is turned by means of the handle 23 to a position in which the manifold 5 via the longitudinal bore 19 of the valve body 18 and its passage 20 communicates with the valve chamber 26 and through it with the outflow channel 27. The pressure conditions at this operating position correspond to the dash-dot line 2 in FIG. 2. Thus, the spray nozzle 8 is connected in parallel to the second flow passage 20 so that the pressure rises more slowly, i.e. that operating pressure Pg is reached correspondingly later than in the case mentioned above. The lower limit value Pu is reached at time t ^, while the upper limit value Pq is reached at a time t ^ p 'the pressure rise time is 12 »25, i.e. substantially longer than the pressure rise time t ^ in normal operation.

The time control means 50 compares the time t 1 with the set reference time selected shorter. Since t 1 is longer than the nominal time, the timing means 50 produces a control signal which via the control line 51 e.g. can be applied to the core in the blending device. In this way, the chemical mixture is activated in the cleaning liquid.

11 DK 169467 B1

In the process according to curve 2, it is assumed that there is no valve body in the valve chamber 26, so that the outflow channel 27 remains open when the pressure reaches the operating pressure Pg. Thereby, some operating pressure Pg is slightly displaced to some extent. However, this displacement is neglected in FIG. 2nd

When the pressure reaches operating pressure Pg, mainly through the spray gun opening nozzle 8 of the spray gun mixed with chemical is sprayed. However, a portion of this liquid-10 amount is discharged through the outflow channel 27. As the user releases the handle 15, the opening 4 is blocked again so that the pressure in the high-pressure line 2 rises until it reaches the cut-off pressure P1, thereby stopping the high-pressure pump 36. When the opening 4 is released again by actuation of the handle 15, the pressure in the high-pressure line drops abruptly until the high-pressure pump is again started at the pressure P ^ n [j · The pressure now rises again, either as shown by curve 2a, when the branching room 5 turns the valve body 18 in the duct 17 again 20 is blocked against the flow ducts 27 and 34, or as shown by the curve 2b when the valve body 18 remains in the same position.

The presence of the valve body 30 in the valve chamber 26 causes the pressure ratios to change slightly.

This is indicated by the dash-dot line 3 in FIG. 2. Even when the valve body 18 is set such that its passage 20 opens into the valve chamber 26, initially, at low pressure, no cleaning medium can pass into the valve chamber 26, because this is blocked by the valve body 30. The valve body 30 is moved first away from its valve seat 29 when the pressure reaches the opening pressure value Pi, 1. This means that the pressure - until it reaches the value - increases at the same speed as in normal operation. As soon as the rotary member 30 is moved away from the valve seat 29, a portion of the cleaning medium can flow through the outlet duct 27. Thus, a pressure increase corresponding to the curve 2. This will be the case until the valve leg 30 is pressed. against the vent in the second valve seat 28 of the chamber 26, thereby blocking the passage to the outflow channel 27 as the pressure reaches a closed pressure, not to increase again, as in normal operation, until it reaches the operating pressure Pg. The pressure rise time t ^ between the time t ^ y> at which the lower limit value Pu of the pressure is reached and the time when the upper limit value PQ is reached is essentially the same as with the curve 2, i.e. longer than the nominal time, so that in this case also a control signal is generated for the supply of chemical. However, it is advantageous, however, when the outflow channel 27 is already blocked shortly before the operating pressure Pg is reached, so that the cleaning medium is then discharged only via the spray nozzle opening 8.

The pressure rise time between the lower limit value Py and 20 the upper limit value PQ can be changed by switching out the outlet channel 34 instead of the outlet channel 27, or by connecting both outlet channels 27 and 34 at the same time. Various pressure rise times can thereby be used to produce different control signals. Thus, e.g. at a short pressure rise time no control signal is produced, while at a medium pressure rise time the chemical supply can be switched on. At a longer pressure rise time, only the burner of the heater can be started, and at a particularly long pressure rise time, both the chemical supply and the burner can be activated.

Of course, for providing different control signals, additional outflow channels may be provided whose flow cross-sections are sized to achieve various pressure rise times.

When the operator wishes to switch from one operating mode to another, only the handle 13 must be released to lock the opening 4. In this position, the handle 23 is rotated to select a new mode of operation, after which the opening 4 is released again by activating the handle. 15. In this way, one can switch from any mode of operation to any other mode of operation. Hereby the switched on chemical supply and / or the activated burner can again be switched off by means of an additional control signal, at which the high pressure pump is stopped when the cut-off pressure Pucj is reached.

Only as examples are given below some numerical values for the various pressures. The operating pressure Pg can e.g.

15 are at 100 bar, the cut-out pressure P ^ at 110 bar, the switch-on pressure P ^ ncj can be 15 bar, the lower limit value Pu can be at 20 bar and the upper limit value Pq at 45 bar. The pressure at which the valve body 30 is removed from the valve seat 29 may be below the inlet pressure Pinc>> e.g. may be 10 bar, while the pressure at which the valve body 30 blocks the outflow channel 27 may lie between the upper limit value Pq and the operating pressure Pg. and e.g. be 70 bar.

In practice, the total pressure rise period can reach up to 25 at normal operation (curve 1 in Fig. 2), at the operating pressure, e.g. be 0.3 seconds. Hereby the pressure rise time t be 0.15 seconds. In the case of slower pressure rise, the time period for obtaining the operating pressure may e.g. increases to 0.7 seconds.

Hereby, the time t2 and t ^ respectively (curves 2 and 3) are e.g. 0.4 seconds.

The pressure rise time between the limit values Pu and Pq can of course also be determined in another way, e.g. by means of a pressure receiver for generating pressure proportional signals, e.g. a piezoelectric crystal or an expandable measuring strip. Two separate pressure sensors may also be provided which output a signal at the lower limit value and at the upper limit value, respectively.

Claims (8)

A method of controlling a high-pressure cleaning apparatus which, through a high-pressure line (2) with a shut-off valve via a spray nozzle (8), delivers a cleaning medium transported by a high-pressure pump (36), the pump being started 5 and stopped in dependence on the pressure in the high-pressure line, the pump is started when the pressure in the high-pressure line has dropped to a value below a switch-on pressure (P d) which is lower than that of the pump at fully or partially open shut-off valve 10 (Pg), characterized in that generating a control signal, a blocking flow passage is coupled parallel to the flow passage through the spray nozzle and, after the pump is started, the pressure rise time in the cleaning medium is determined and upon the release of one of the second flow passage conditional extension of the pressure rise time period in relation to pressure rise. flow passage generates a control signal. Method according to claim 1, characterized in that the second flow passage is blocked most recently when the pressure reaches the operating pressure value (Pg). A high-pressure cleaning apparatus for carrying out the method according to claim 1 or 2, with a high-pressure pump (36), a high-pressure line (2) leading from it to a spray gun (7) with a shut-off valve and with an upstream of this arranged pressure sensor which delivers a high-pressure pump triggering signal when the pressure in the high-pressure line drops below a switch-on pressure (P 2), characterized in that a first flow passage in the spray gun (7) leading from the high-pressure line (2) to the spray gun's pipe (7) leads into the spray gun. 16, there is an optional blocking second flow passage including outflow channels (27, 34), that the high pressure line (2) communicates with a pressure sensitive signal transducer (48) connected to a timing means 5 (50), and the timing means is arranged to output a control signal when the pressure rise time (t) between two specific pressure values, namely a lower limit value (P) and an upper limit value, value (Pq) exceeds a certain value after the high pressure pump (36) start. A high-pressure cleaning apparatus according to claim 3, characterized in that the pressure-sensitive signal generator has two pressure sensors which at different pressures supply the time means (50) each with its own signal. A high-pressure cleaning apparatus according to claim 3 or 4, characterized in that the pressure-sensitive signal generator includes a maneuverable means (41, 46) which is displaceable against a spring means (44), which in one position influences one with the timing means (50). connected switch (48). High pressure cleaning apparatus according to claim 5, characterized in that the actuator (41, 46) cooperates with a switch (48) which is connected by the actuator (41, 46) when the pressure in the high pressure line reaches a lower limit value (P). , and which is brought back to the interrupted position by the actuator when the pressure reaches an upper limit value (P). High pressure cleaning apparatus according to any one of claims 2 to 6, characterized in that the control signal running 3 sets a dosed admixture of a chemical in the cleaning medium 4 30 and / or a burner in a heating device. DK 169467 B1 17 High-pressure cleaning apparatus according to any of claims 3-7, characterized in that the second flow passage is branched from the first flow passage downstream of the high-pressure conduit shut-off valve (4, 10). High pressure cleaning apparatus according to claim 8, characterized in that a metering valve consisting of a throttle opening (6) and a throttle body (11) is arranged in the first flow passage with an injection channel (7) downstream of the shut-off valve (4, 10). ), and that the second flow passage is branched from the first flow passage upstream of the metering valve. High pressure cleaning apparatus according to any one of claims 3-9, characterized in that a manually operated shut-off valve with a valve body 13 (18) is provided for the second flow passage. A high-pressure cleaning apparatus according to any one of claims 3-10, characterized in that a valve body (30) is disposed in the second flow passage which is displaceable against the action of this actuating spring member (31) 20 in a locking position in which adjoins a valve seat (28), thereby blocking the second flow passage, most recently when the pressure reaches the operating pressure value (Pg). High pressure cleaning apparatus according to claim 11, characterized in that the valve body (30) is held in resting state by the spring means (31), pressed against an upstream valve seat (29) upstream of the valve body, thereby blocking the second flow passage and the valve body (30). ), when removed from this valve seat (29), 30 forms a throttle member in the second flow passage. DK 169467 B1 18 High-pressure cleaning apparatus according to any one of claims 3-12, characterized in that it is arranged for connecting at least one additional parallel flow passage (34) to the first flow passage (7) 3 and the second flow passage (27) and to the timing means (50 ) is adapted to output various control signals when the pressure rise time is extended to varying degrees with respect to the pressure rise time corresponding to only the first flow passage (spray line 10 7) being open.